[libvirt] [PATCH 2/3] virnetsocket: Resolve Coverity RESOURCE_LEAK
John Ferlan
jferlan at redhat.com
Fri Aug 22 16:48:58 UTC 2014
On 08/22/2014 12:42 PM, John Ferlan wrote:
>
>
> On 08/22/2014 11:49 AM, Michal Privoznik wrote:
>> On 22.08.2014 17:28, John Ferlan wrote:
>>> Since '1b807f92d' - Coverity complains that in the error paths of
>>> both virFork() and virProcessWait() that the 'passfd' will not be closed
>>>
>>> Signed-off-by: John Ferlan <jferlan at redhat.com>
>>> ---
>>> src/rpc/virnetsocket.c | 8 ++++++--
>>> 1 file changed, 6 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c
>>> index f913365..ce908fa 100644
>>> --- a/src/rpc/virnetsocket.c
>>> +++ b/src/rpc/virnetsocket.c
>>> @@ -593,8 +593,10 @@ int virNetSocketNewConnectUNIX(const char *path,
>>> * behaviour on sockets according to POSIX, so it doesn't
>>> * work outside Linux.
>>> */
>>> - if ((pid = virFork()) < 0)
>>> + if ((pid = virFork()) < 0) {
>>> + VIR_FORCE_CLOSE(passfd);
>>> goto error;
>>> + }
>>>
>>> if (pid == 0) {
>>> umask(0077);
>>> @@ -604,8 +606,10 @@ int virNetSocketNewConnectUNIX(const char *path,
>>> _exit(EXIT_SUCCESS);
>>> }
>>>
>>> - if (virProcessWait(pid, &status, false) < 0)
>>> + if (virProcessWait(pid, &status, false) < 0) {
>>> + VIR_FORCE_CLOSE(passfd);
>>> goto error;
>>> + }
>>>
>>> if (status != EXIT_SUCCESS) {
>>> /*
>>>
>>
>> Unfortunately not enough context is shown to express myself, so I'll paste interesting knobs from the function:
>>
>> if (listen(passfd, 0) < 0) {
>> virReportSystemError(errno, "%s",
>> _("Failed to listen on socket that's about "
>> "to be passed to the daemon"));
>> goto error;
>> }
>>
>> if (connect(fd, &remoteAddr.data.sa, remoteAddr.len) < 0) {
>> virReportSystemError(errno, _("Failed to connect socket to '%s'"),
>> path);
>> goto error;
>> }
>>
>> if (virNetSocketForkDaemon(binary, passfd) < 0)
>> goto error;
>> }
>>
>> localAddr.len = sizeof(localAddr.data);
>> if (getsockname(fd, &localAddr.data.sa, &localAddr.len) < 0) {
>> virReportSystemError(errno, "%s", _("Unable to get local socket name"));
>> goto error;
>> }
>>
>> if (!(*retsock = virNetSocketNew(&localAddr, &remoteAddr, true, fd, -1, 0)))
>> goto error;
>>
>> return 0;
>>
>> error:
>> VIR_FREE(buf);
While implementing the change to add passfd here - I noticed that buf is
never used in this context? Strange. There's an initialization to NULL
and a VIR_FREE(buf);, but nothing else uses it, so I removed it.
John
>> VIR_FORCE_CLOSE(fd);
>> if (spawnDaemon)
>> unlink(path);
>> return -1;
>> }
>>
>>
>> Here, if any of listen() or connect() fail, the control continues on the error label and the @passfd is leaked again.
>> virNetSocketForkDaemon() is different - it closes passfd on failure. So I suggest moving VIR_FORCE_CLOSE() under the error label.
>>
>
> Yeah - Coverity only complained about the two paths - so I was hesitant
> to put the VIR_FORCE_CLOSE(passfd) in the error: path...
>
> In any case, putting it the error: path does resolve the issue as well
> as making sure to initialize passfd = -1 (initializing fd = -1 wasn't
> necessary since there's currently no way to error unless it's set)
>
> John
>
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